It's plainly true that spending several billion preventing climate change now, will prevent having to spend several trillion dollars later. There is no debate about that. But the people with the billions now do not want to give it up, so they have spent decades destroying trust in experts, so people will be tricked into voting for their children to spend trillions later, so that the current billionaires don't have to spend anything now.
It's the same thing pushing anti-vaccine views, even though people getting needlessly sick is obviously bad for the economy. Don't trust your doctor, "do your own research" because you know better than the experts, etc etc. It's all part of getting people to vote against their own interests. A stupid population is easier for the powerful to maintain control over than an educated one.